Voice over Internet Protocol (VoIP)-based Push-to-Talk (PTT) technologies allow a user to utilize multiple mobile devices when engaging in a PTT call. For example, a mobile device user may own multiple mobile devices, such as a smartphone, a wireless-enabled laptop computer, and a wireless-enabled tablet computer, that all operate on a same wireless network. Similarly, a Public Safety officer may have multiple mobile devices, such as a smartphone, a Land Mobile Radio (LMR), a wireless-enabled laptop computer, and a vehicle-mounted laptop computer, that may all be capable of engaging in a Push-to-Talk communication involving the officer.
The Session Initiation Protocol (SIP) supports SIP forking, wherein the multiple mobile devices of a user may each be rung when a VoIP or a PTT call is set up. Thus a call may be targeted to, and received by, all of the mobile devices of a user. However, with respect to PTT, call setup often is automatic on the multiple mobile devices of a user, with the result that all of the user's mobile devices may start rendering audio. This could be annoying to anyone in the vicinity of a user's mobile device if the user has left that mobile device behind when roaming to a different location with another one of the user's multiple mobile devices. Further, this could result in public exposure of a PTT call that is intended to be private. In addition, this is bandwidth inefficient as calls that are auto joined are setup to, and media is transmitted to, the multiple devices of a user.
One of ordinary skill in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present invention. Also, common and well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required.